Percents

Percent Change/Difference = 100 * [(B/A) - 1] where B is the 2nd number given and A is the 1st.

Example:

 

B = area of letter-sized sheet = 8.5*11 = 93.5
A = area of legal-sized sheet = 8.5*13 = 110.5

% change = 100 * [(93.5/110.5)-1] = -15.4 or -1.54x10^1

Percent Error = 100 * [(approximate/exact) -1]

Example:

Approximate = 1152
Exact = 1176.37
Percent Error = 100 * [(1152/1176.37)-1] = -2.07 (notice that this is an SD problem and is 3 sig figs)

-Kevin